Brake.



J. T. LEONARD.

BRAKE.

APPLICATJON FILED JAN-29,1913.

1,159,238, Patented-Nov. 2, 1915.

2 SHEITS-SHEET I.

QQLQ 2 W Allorneys' J. T. LEONARD.

BRAKE.

. APPLICATION FILED JAN. 29. 19I3.

Patented Nov. 2, 1915.

2 SHEETS-SHEET 2- INVENTOR AIE WITNESSES UNITED SAT ATENT onion.

JOHN T. LEONARD, F WICHITA, KANSAS.

BRAKE.

1,159,238, Specification of Letters Patent.

Patented Nov, 2, 19156 Application filed January 29, 1913. Serial No.744,904.

. To all whom it may concern:

Be it known that 1, JOHN '1. LEONARD, a citizen of the United States,residing at Wichita, in the county of Sedgwick and State of Kansas, haveinvented certain new and useful Improvements in Brakes, of which thefollowing is a specification.

My invention relates to an improvement in brakes and more particularlyto a friction brake which is operated by electrical means.

This brake is to be used in connection with an electric or other motorand is designed to automatically apply the brake and stop the motor whenthe current to the motor is cut off.

It is also designed to automatically release the brake when the motorcurrent is applied and to permit normal running of of parts which willbe hereinafter more fully described and pointed out in the claims.

In the accompanying drawingsFigure 1 is a view in side elevation showingthe device as applied to a. motor; Fig. 2 is a View in end elevation ofthe mechanism disclosed in Fig. 1; Fig. 3 is aview in perspective of themain operating parts showing them detached, and Fig. 4: is a detail viewof the dental connection in the clutch operating shaft.

The motor A hasa brake drum 1 secured on the shaft a thereof.- Brakeshoes 2 and 3 are provided to fit the outer circumference of the drum 1.A base 4: is secured vertically beneath the drum and the shoes 2 and V 3are pivoted by pins 5 in position to swing against and embrace the drum1.

Brackets 6 are formed on the upper free ends of the brake shoes 2 and 3.An open ing 7 is provided through each of the brackets 6 to be inparallel alinement and through these openings 7 a rod 8 is received.Springs 9, 9, are received on the ends of the rod 8 to bear against theouter face of the bracket 6 and their tension is adjusted through themedium of nuts 10, 10 which are received on the screw threaded ends ofthe rod 8. In this way the brake shoes 2 and 8 are normally held inengagement with the brake drum 1 secured on the shaft 41 of the motorand the motor will be held against starting.

On the inner face of each of the brackets 6, a bearlng 11 is providedand a yoke 12 is pivoted by a pin 13 to each of these bearings. On theupper end of the yokes 12, friction wheels 14, 14 are journaled torevolve on the pins 15, 15. A brake shaft 16 is mounted to extendbetween the friction wheels 14 and to have its center on a line drawnbetween the axis of rotation of the two wheels. 1

A roll 17 is secured on the brake shaft 16 between the wheels 14 and attwo points diametrically opposite the roll 17 is cut away to have theflat sides 18. Adjusting screws 19. are received through the brackets 6and bear on their ends against theyokes 12 so that the friction wheels14: will, when the brake shoes 2 and 3 are seated against the brake drum1, come in contact with the flat Sides 18 of the roll 17. From this itwill be Seen that if the roll is turned a part revolution, say ofapproximately 90 degrees or one quarter (1}) turn, the full diameter ofthe roll will be brought between the friction wheels 14, 14 carried onthe brake shoes 2 and 3 and they will be forced outwardly away from theframe drum 1 against the tension of the springs 9 which bear against thebrackets 6, thus releasing the brake and permitting free rotation of themotor shaft a on which the brake drum 1 is secured.

As a means of rotating the shaft 16, I have provided a field structure19 which has the two poles 20 and 21 provided with the usual coils 22and 23 respectively for energizing them. An armature 2 1 is mounted onan armature shaft 25 within the field structure and a weight 26 securedon the end of the armatureshaft' holds the armature normally in aposition with its operating faces away from the pole faces, as bettershown in Fig. 3, the movement of the weight 26 downwardly andconsequently the position at which the armature normally reposes beingfixed by a stop 27 carried on the field structure.

The brake shaft 16 and the armature shaft 25 are mounted to be inalinement and to revolve on the same axis, as it were. The shaft 16carries the toothed member 28 of a dental coupling and the socket member29 is shown in this instance as being formed on the weight 26 secured tothe armature shaft.

The wires 30 and 31 which lead to the motor A, are connected to theusual switch 32 and thence with the line wires. The wires 33 and 34,which connect with the coils 22 and 23 respectively of the field poles,are connected to the wires 30 and 31 leading to the motor.

The operation of the device is as follows- When the parts are in theposition shown in Figs. 1, 2 and 3, with the switch open, the motorwould not be energized and would not have movement. The brake shoes 2and 3 are in their normal position with their operating faces bearingagainst the brake drum and the motor shaft is held against rotation.When the switch 32 is thrown to connect with the line wires, the currentpasses through the Wires 30 and 31 to the motor and consequently throughthe wires 33 and 34 to the coils of the field structure. The fieldstructure is energized and the armature 24 is brought to a positionparallel with the field poles. This gives the armature shaftapproximately a quarter turn and the shaft is held against furtherrotation by the weight 26 engaging with a stop 35 carried by the fieldstructure. As the dental coupling connects the armature shaft with thebrake shaft, the brake shaftwill turn a like distance and the roll 17will be rotated so that its full diameter will be brought between thefriction wheels 14, 14 carried by the brake shoes 2 and 3. This forcesthe brake shoes away from the brake drum against the tension of thesprings 9 and permits the motor shaft a to be rotated due to the currentpassing through the wires 30 and 31. When the switch is thrown out tostop the motor, the current through wires 33 and 34 to the field coilsis also cut off, which denergized the field poles. The armature shaft isagain turned to bring the armature out of its parallelism with the fieldpoles through the weight 26, and as the armature shaft and the brakeshaft are connected by the dental ,coupling the roll will again beturned and a position with its fiat sides between the friction wheels14, 14, and the vided which may be used in connection with an electricelevator or any other means where it is desirable that when the switchis thrown to cut ofi the power the motor is stopped immediately, and asthe curved sides of the roll 17 are perfect arcs of a center taken onthe axis of rotation of the brake shaft, and the friction wheels 14 arealso perfect arcs, the brake shaft cannot be forced through the tensionof the springs 9, and the operation will always be positive. Also, itwill be seen that this structure as shown and described'can be used witheither alternating current or'direct current and that slightmodification might be made in the form, proportion and minor detailswithout departing from thespirit or scope of my invention and it will beunderstood that I do not wish to limit myself to the exact constructionherein set forth, but

Having fully described my invention, what I claim as new and desire tosecure by Letters Patent is- 1. In a brake, the combination with a drum,of shoes normally in engagement with the drum for holding the drumagainst movement, means for spreading the shoes apart to release'thedrum, means for actuating said means, magnetic means for operating saidlast mentioned means whereby the spreading means is actuated for causingthe shoes to release the drum, said actuatingmeans and magnetic meansnormally out of engagement, and adapted to be brought into engagementupon the operation of the mag:

netic means and means for operating said actuating means to cause saidspreading means to return to its normal position.

2. In a brake, the combination with a drum, of shoes normally inengagement with the drum for holding the drum against movement, meansfor spreading the shoes apart to release the drum, means for actuatingsaid means, magnetic means for operatingsaid last mentioned meanswhereby the spreading means is actuated for causing the shoes to releasethedrum, said actuating means and magnetic means normally out ofengagement and adapted to be brought into engagement upon the operationof the magnetic means.

3. A brake comprising, in combination with a motor and brake-drumsecured to the shaft, brake-shoes pivoted adjacent the drum and inposition to fit and engage therearound, spring-pressed means for holdingthe shoes normally in engagement with the drum, projections carried bythe free ends of the shoes, a shaft mounted to turn between saidprojections, a cam secured to the shaft and shaped to normally permitthe engagement of the shoes with the drum, and when turned to engagewith the projections to move the shoes from their engagement with thedrum, a second shaft mounted in alinement with said cam-shaft, acoupling between said shafts, magnetic means for turning said secondshaft so that the first shaft is brought to a position with the cam inoperative relation between the projections, and a weight carried by saidsecond shaft in position to turn said first shaft when the magneticmeans is deenergized so 10 that the cam occupies its normal position.

In testimony whereof I affix my signature, in the presence of twowitnesses.

JOHN T. LEONARD. Witnesses:

NORMAN H. BEEBE, GEORGE B. COLE.

